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The singer and songwriter now known as Yusuf Islam has been barred from entering the United States, based on intelligence information gathered just weeks ago linking him to terrorist organizations, U.S. officials said.

Mr. Islam, accused of contributing to terrorist organizations, was forced to return to his home in London last night.

Officials say donations from Mr. Islam ultimately went to Sheik Omar Abdel-Rahman, the blind cleric convicted for the 1993 World Trade Center bombing, and to Hamas, a Palestinian terrorist group.

Mr. Islam, born Stephen Georgiou, recorded a string of hits — including “Wild World,” “Peace Train” and “Morning Has Broken” — in the 1970s under the stage name Cat Stevens. He changed his name again in 1977 when he became a Muslim and temporarily abandoned his music career.

Tuesday, he was taken from United Flight 919 from London Heathrow to Washington Dulles International after the plane was diverted to Bangor, Maine. U.S. officials said airline employees in London failed to check his name against terrorist watch lists, to which Mr. Islam was recently added.

“United messed up out of Heathrow,” said one Homeland Security Department official. “He came up on a positive watch list and they should have denied him access to the plane. He was on several watch lists.”

The error was discovered when U.S. Customs and Border Patrol officials began their check of passengers coming into the country and ordered the plane be diverted. Mr. Islam was questioned separately by three agencies that are part of the FBI Joint Terrorist Task Force, and denied entry. He was held at the Bangor airport overnight Tuesday then moved to Dulles Airport yesterday and returned to London last night.

Mr. Islam was accompanied by his daughter, who was allowed to enter the United States, but officials said yesterday they expected her to return to London with her father.

Mr. Islam’s most recent visit to the United States was in May to promote a DVD of his 1976 concert tour and to attend a charity event in New York. That was before federal officials put him on no-fly status.

Mr. Islam was denied entry to Israel in 2000 and was accused of donating money to Hamas. The singer’s brother and business manager, David Gordon, told the Associated Press his brother does not associate with potential terrorists.

“It’s not true. His only work, his only mind-set, is humanitarian causes. He just wants to be an ambassador for peace,” Mr. Gordon said.

The Council on American-Islamic Relations yesterday criticized the Bush administration for ejecting Mr. Islam from the United States, saying the action “sends the message to the Islamic world that even those who seek peace and condemn terror are not fit to enter the United States.”

The Homeland Security official said the agency was “very confident” about its information on Mr. Islam. “This is recently developed information in the past several weeks, and we felt he should not be flying into the U.S.,” the official said.

One of the charities Mr. Islam founded is the Waqf al Birr Trust. According to an Amnesty International report, the Kosovo offices of Waqf al Birr Trust were raided in December 2001 by an international coalition of law enforcement for suspected terrorist activities. One employee was arrested.

According to Mr. Islam’s Web site, he established Waqf al Birr in 1992 to promote education and scientific and medical research, and to alleviate poverty.

After the September 11 terrorist attacks, Mr. Islam pledged to donate proceeds from a four-CD “Cat Stevens Box Set” to the September 11 Fund. He has vocally criticized terrorism and condemned the recent attack on a school in Beslan, Russia.